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Category 1: Buildings
With the aim of ensuring environmental sustainability
in construction, a mixed material was developed,
composed of bamboo and filled with concrete,
combining the advantages of both materials in a single
element.
In general, the bamboo constructs are still made
empirically based on the results of the field load test.
These buildings tend to conform more to traditions,
beliefs and criteria established by professionals than
to standards calculation or mathematical models for
structural analysis. Therefore, in order to simulate
the behaviour of these structures we chose to model
a building of four floors in Scia Engineer structural
analysis software developed by the Nemetschek Scia.
The performance of experimental research was
essential for defining the characteristics of bamboo
filled with concrete. By means of tests in the laboratory
of the “Instituto Mauá de Tecnologia”, we studied the
mechanical behaviour of the composite to bending,
compression and shear, adjusting the physical and
mechanical properties together with parameters of the
input for Scia Engineer.
Materials
C25/C30 concrete was used with the physical and
mechanical characteristics stipulated by the European
standard Eurocode (EN 1992).
To simulate the characteristics of bamboo the woods
were chosen as the base material, once the bamboo
had different behaviour in relation to the position of the
material fibres. Through literature and testing developed
by the authors, the physical and mechanical properties
of bamboo were stipulated.
Cross Section
The default values adopted for the bamboo poles were
15 cm in diameter and 1.50 cm thickness.
Structural Model
The model includes a 3D portico, with four floors
composed of bamboo stick pillars, and bamboo beams
filled with C25/C30 concrete.
Loads
The usual design procedures were followed, respecting
the precepts of technical standard NBR 6120: “Loads
for the calculation of structures”, aimed at simulating
the loads of dead weight of the slabs, closing masonry,
dry-wall and overhead of utilisation. Loading due to
wind was not considered, as it is a structure with high
rigidity, low overall height and a great number of pillar
rows. The self-weight load was applied automatically by
Scia Engineer, taking into account the specific weight
of the materials used. All the loads, both permanent
and accidental, were increased by 1.40, according to
NBR 6118.
Theoretical Verification
Through the internal forces in the bars, from the
structural analysis developed in Scia Engineer, the
bars more requested were verified by applying criteria
of strength of materials to normal stresses and shear
stresses.
Conclusion
All bars met the verification criteria, making it possible
to state that a four-floor building made of bamboo is
technically feasible.
The bamboo has good compressive strength, enough
to be used in the columns of the building. However, the
beams require sections of bamboo filled with concrete.
The bamboo is efficient in normal forces, both traction
and compression, hence its use in truss structures
provides better utilisation of its resistance, but does
not exclude other structural models, such as those
presented in this work.
It has been proven throughout the development of the
research that bamboo is an alternative material for the
construction industry and besides having good physical
and mechanical characteristics it is a material that
enhances sustainability.
Software: Scia Engineer
Structural Analysis of a Bamboo Building - Brazil
